Coaxial switch structure and method of making same



May 22, 1956 F. E. COCKERHAM ETAL 2,747,059

COAXIAL SWITCH STRUCTURE AND METHOD OF MAKING SAME Filed May 23, 1952 Fran/r E. ckerfim COAXIAL SWITCH STRUCTURE AND METHOD OF MAKING SAIVIE Frank E. Cockerham, Parma, and John A. Darlro, Cleveland, Ohio, assignors to Thompson Products, Inc, Cleveland, Ohio, a corporation of Ohio Application May 23, 1952, Serial No. 289,582

10 Claims. (Cl. 200-166) This invention relates to a coaxial switch, and more particularly, to a coaxial switch rotor assembly.

Heretofore, it has not been thought possible to utilize a non-moldable plastic material, such as polytetrafiuoroethylene resin (commonly known as Tefion) in the curved elbow passage of a coaxial switch rotor. Teflon is desirable for this use because of its electrical advantages such as low power loss and low dielectric constant, as well as its satisfactory temperature and other physical characteristics.

It is, therefore, an important object of the present invention to provide a method for inserting non-moldable plastic material in a curved passage, such as the curved elbow passage of a coaxial switch rotor.

It is a further important object of the present invention to provide a method for inserting such a material in a curved passage without substantially altering the uni form dielectric characteristics of the material.

It is a further important object of the present invention to provide a novel coaxial switch rotor.

In accordance with one form of the method of the present invention, a straight tubular sleeve of Teflon or other non-moldable plastic material is split into two halves in a plane lengthwise to the central axis of the bore of the sleeve, and with the inner conductor maintained coaxially in the curved passage, the two split halves are more or less simultaneously driven into said passage as by tapping first one half and then the other half successively, one half traveling along the shortest curvature of the passage and the other half along the longest.

According to a further feature of the method of the present invention, the two halves are driven until both halves project beyond the other end of the elbow passage, the projecting portions then being severed so that the highly stressed condition of these portions will not alter the uniform dielectric characteristics of the halves in the final switch.

Other and further important objects and features of the present invention will be apparent from the disclosures in the specification and the accompanying drawings.

On the drawings:

Figure 1 is a perspective view of a tubular insulating sleeve of polytetrafluoroethylene prior to insertion in the elbow passage of a rotor;

Figure 2 illustrates the sleeve of Figure 1 after it has been split longitudinally in preparation for insertion into the elbow passage of a rotor;

Figure 3 is a vertical sectional view illustrating the split halves of the sleeve being inserted into the elbow passage of a rotor in accordance with the method of the present invention;

Figure 4 is a vertical sectional view similar to Figure 3, but showing the halves completely driven into the rotor elbow passage; and

Figure 5 is a vertical sectional view illustrating a finished rotor in accordance with the principles and teachings of the present invention.

fnited States Patent Q ,7 2,741,059 Patented May 22, 1956 As shown on the drawings:

As illustrated in Figures 1 and 2, a straight tubular sleeve 10 of non-moldable plastic material, such as polytetrafiuoroethylene resin, has a central bore 11 extend ing therethrough. The sleeve is to be inserted in a curved passage such as the elbow passage in a rotor of a coaxial switch. As illustrated in Figure 2, the tubular sleeve 10 is split longitudinally as indicated at 15 to form two semitubular halves 13 and 14 having semi-circular grooves, 11 and 11".

In accordance with the present invention, the inner elbow conductor 16 is held in coaxial relationship to the wall 17 of an elbow passage 18 of the coaxial switch rotor 19. The semi-tubular halves 13 and 14 are then inserted between the inner conductor 16 and the wall 17 in such a manner that one half 13 is adapted to fill the upper shortest curvature portion of the elbow passage indicated at 21, while the other half 14 is directed to the longest curvature portion of the elbow passage indicated at 22. The insulation sleeve halves are then driven more or less simultaneously into the passage by tapping first one half and then the other half so that the two halves interact with each other and with the inner conductor to conform to the contour of the elbow passage 18. For example, the long curvature half 14 underlies and tends to support the inner conductor 16, as the short curvature half is driven forward and constrained by the inner conductor 16 to bend toward the end 23 of passage 18.

As indicated in Figure 4, the sleeve halves are driven so that the forward ends indicated at 24 and 25 project beyond the opposite end 23 of the passage and may thus be severed so as not to form a part of the finished rotor. The purpose of this procedure is to avoid a variation in dielectric characteristics due to the higher stresses which are exerted on the forward portions 24 and 25 of the halves in the process of driving the halves into the passage. These stresses would otherwise alter the dielectric characteristics of the forward portions 24 and 25.

As indicated in Figure 5, the upper end of the inner conductor and the upper peripheral portion of the rotor, as well as the projecting portion of the insulation halves are trimmed off to form the finished rotor assembly. This finished rotor assembly includes an inner conductor 30 having a pin 31 at its upper end and a notched contact portion 32 at its lower end. The inner conductor is supported in coaxial relation to the elbow passage 18 by short curvature insulation sleeve half 34 and long insulation sleeve half 35. As indicated in Figure 5, a pair of Teflon pins 37 and 38 may be driven into the sleeve halves 34 and 35 to retain the halves in position in the rotor. A finished rotor such as herein illustrated is suitable for use, for example, with the coaxial switch illustrated in the copending application of Carl F. Schuncmann and Theodore R. Thoren, Serial No. 267,246, filed January 19, 1952, and assigned to the same assignee as the present application. While the invention has been described as applied to a rotor passage in an axial plane by way of example, the present invention is also applicable to an elbow passage extending in a radial plane relative to the rotor axis.

It will, of course, be understood that various details of construction and method of manufacture may be varied through a wide range without departing from the principles of the present invention, and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

We claim as our invention:

1. The method of inserting solid deformable material in a curved passage which comprises selecting a plurality of straight parts of said deformable material together corresponding to the cross-section of said passage, driving one of said parts into said passage along one curved path thereof to deform said one part into conforming relation to said one path, and driving another of said parts into said passage along a second path to deform said another part into conforming relation to said second path.

2. The method of inserting solid deformable material in a curved passage which comprises selecting a plurality of straight parts of said deformable material together corresponding to the cross-section of said passage, driving one of said parts into said passage along a first curved path thereof to deform said one part into conforming relation to said first path driving another of said parts into said passage along a second path to deform said another part into conforming relation to said second path, driving at least one of said parts to project beyond the opposite end of said passage, and removing the projecting portion thereof.

3. The method of inserting a straight length of solid deformable dielectric material into a curved outer conductor passage of a coaxial circuit, the passage having a path, and driving another of said parts into said passage along said relatively short path.

4. In a method of assembling solid deformable dielectric material in a curved passage of a coaxial circuit element, the passage having a relatively long curvature path and a relatively short curvature path, the steps which comprise selecting a plurality of straight parts of said dielectric material, driving one of said parts into said passage along said relatively long path and driving another of said parts into said passage along said relatively short path.

5. The method of inserting solid deformable dielectric material in a curved outer conductor passage of coaxial switch, the passage having a relatively long curvature path and a relatively short curvature path, which comprises selecting a plurality of straight parts of said deformable material together corresponding to the cross section of said passage, driving one of said parts into said passage along said relatively long path and driving another of said parts into said passage along said relatively short path, driving at least one of said parts to project beyond the opposite end of said passage, and removing the projecting portion thereof.

6. The method of inserting solid deformable dielectric material into a curved passage of coaxial circuit element, the passage having a relatively long curvature path and a relatively short curvature path, which comprises supporting an inner curved conductor coaxially in said curved passage, selecting a plurality of straight parts of said deformable material together adapted to support said inner conductor in coaxial relation within said passage, and generally alternately driving first one of said parts then another of said parts progressively into said passage between the wall of said passage and said inner curved conductor to deform said parts to conforming relation to said passage.

7. In a method of making a coaxial switch rotor of the type having a curved elbow passage therein providing a relatively long curvature path and a relatively short curvature path, the steps which comprise supporting an inner elbow conductor coaxially in said elbow passage, inserting straight segmental tubular parts of deformable dielectric material into one end of said passage between the wall of said passage and said inner elbow conductor, with one of said parts aligned with. a relatively short curvature path and another of said parts aligned with a relatively long curvature path, and contemporaneously driving said parts into said curved elbow passage.

8. In a method of making a coaxial switch rotor of the type having a curved elbow passage therein providing a relatively long curvature path and a relatively short curvature path, the steps which comprise supporting an inner elbow conductor coaxially in said elbow passage, inserting straight segmental tubular parts of deformable dielectric material into one end of said passage between the wall of said passage and said inner elbow conductor, with one of said parts aligned with a relatively short curvature path and another of said parts aligned with a relatively long curvature path, contemporaneously driving said parts into said curved elbow passage, and driving retaining pins of dielectric material transversely into said parts to retain the same in position in said passage.

9. In a method of making a coaxial switch rotor of'the type having a curved elbow passage therein, the steps of supporting an inner elbow conductor coaxially in said elbow passage, inserting straight segmental tubular parts of deformable dielectric material into one end of said passage between the wall of said passage and said inner elbow conductor, contemporaneously driving said parts into said curved elbow passage, driving said parts to project beyond the opposite end of said passage, and severing the forward projecting portions of the parts from the remainders thereof.

10. In a coaxial switch, a solid rotor having a curved elbow passage therein, a pair of semi-tubular sections respectively extending along the long and short curvature paths of said passage, and a conductor mounted coaxially within said passage by said sections, said sections being bent into said curvature paths so as to be urged by their inherent resiliency into frictional engagement with each other, with said conductor and with the interior surfaces of said passage.

References Cited in the file'of this patent UNITED STATES PATENTS 2,277,637 .Eby Mar. 23, 1942 2,365,785 Tinnerman Dec. 26, 1944 2,565,643 Baddour Aug. 28, 1951 

